The Muslim Brotherhood today dismissed a timetable for new elections in Egypt after at least 51 people were killed at a protest outside a barracks in Cairo.

Adly Mansour, who was imposed as interim president by the army last week after the ousting of Islamist leader Mohamed Morsi, rushed out the promise of elections early next year in a bid to stop violence escalating across the country.

But Essam al-Erian, a senior official of the Muslim Brotherhood, said the plan for constitutional changes, parliamentary elections and then a presidential vote just “brings the country back to square one”. The Brotherhood, Egypt’s main Islamist movement which has condemned the coup against Mr Morsi, is calling for fresh protests and an uprising against the new administration. It said soldiers opened fire with live ammunition and tear gas on demonstrators praying in the early hours yesterday outside the Republican Guards barracks where Mr Morsi is believed to be detained.

Amid the conflicting accounts, the shocking death toll dealt a huge blow to hopes of stabilising Egypt to avoid a bloody civil war.

Eight women and four children were reported to be among the 51 killed, with more than 400 injured.

Several witnesses said soldiers opened fire indiscriminately on the protesters, though others said they had first come under fire.

Responding to the escalating crisis, Mr Mansour pledged to set up within 15 days a panel to amend the Islamist-drafted constitution, with the changes being put to a referendum within four months, leading to parliamentary election.

Once parliament convened, a presidential election would then be held shortly afterwards.

In what appeared to be an olive branch to Islamists, Mr Mansour’s decree included controversial language put into the constitution last year that defined the principles of Islamic sharia law.

But the Muslim Brotherhood today accused the army of trying to “steal” the governance of Egypt from Mr Morsi, the country’s first freely-elected president.

The carnage at the demonstration at the Cairo barracks has shocked Egyptians.

Many are already tired of the clashes and violence that started more than two years ago after the overthrow of autocratic ruler Hosni Mubarak in a popular uprising.

Amid concerns in America, Britain and other countries over Egypt’s future, the United Nations said it was “gravely concerned” about mounting violence and said the country was on a “precarious path.”